Related Experiment Videos
Expectancy effects in caffeine research
L Christensen1, B White, K Krietsch
1College of Liberal Arts, Texas A & M University, College Station 77843-4235.
The International Journal of the Addictions
|January 1, 1990
Abstract:
The impact of expectancy on the experience of caffeine-related symptoms was investigated by randomly assigning subjects to an expectancy or nonexpectancy instructional condition. Subjects were administered the State-Trait Anxiety Inventory and a Symptom Questionnaire prior to and 45 minutes after receiving their designated instructional set and ingesting a cellulose-filled gelatin capsule which ostensibly was filled with caffeine. Results revealed that a significant expectancy effect existed on five Symptom Questionnaire items.